Oldest Dialysis Population Exploding

Number of octogenarians and nonagenarians starting dialysis increasing by about 10% annually.

Researchers report a dramatic increase in the number of patients in their 80s and 90s starting dialysis.

The number of octogenarians and nonagenarians who initiated dialysis soared from 7,054 in 1996 to 13,577, for an annual increase of 9.8%. When the investigators ac-counted for population growth, the rate of dialysis initiation in this age group rose by 57% during that period. The average annual increase in the U.S. population was 2.3% among those aged 80-84 years and 3.2% among those aged 85 years and older.

By comparison, the average annual increase in dialysis initiation from 1996 to 2003 among patients aged 65-79 years was only 3.5% and the U.S. population of individuals in that age group did not increase substantially.

The researchers, led by Manjula Kurella, MD, MPH, of the University of California in San Francisco, speculate that the swelling number of the very-oldest patients may be related to dialysis initiation at higher estimated glomerular filtration rates (eGFR), more liberal admission to dialysis programs, or both. Their study showed that subjects who started dialysis in 2003 had a higher eGFR than those who started in 1996. The investigators reported their findings in the Annals of Internal Medicine (2007;146:177-183).

“Although dialysis may increase life expectancy for selected octogenarians and nonagenarians, overall survival times remain modest,” the authors wrote. “When considering dialysis initiation among the elderly, decision-making should be individualized and realistic estimates of survival should be considered along with expected quality of life and the patient's values.”

The rate of dialysis initiation from 1996 to 2003 increased by 50% among individuals aged 80-84 years versus 72% for those aged 85 years and older. The rate rose by 54% for men and 61% for women, 64% for whites and 45% for blacks.

The octogenarians and nonagenarians had a 46% one-year mortality rate after starting dialysis. Median survival after starting dialysis was 15.6 months for patients aged 80-84 years, 11.6 months for those aged 85-89 years, and 8.4 months for subjects aged 90 years and older.

The average life expectancy in the general population for individuals aged 80-84, 85-89, and 90-94 years is 105, 78, and 57 months, which is 89, 66, and 48 months longer than the average life expectancy of patients aged 80-84, 85-89, and 90 years and older, respectively, who are starting dialysis, the researchers observed.

“Regardless of the exact causes,” the investigators observed, “the dramatic increase in dialysis initiation among octogenarians and nonagenarians has important implications for researchers, health care providers, and policymakers.” They noted, for example, that the applicability of dialysis guidelines to very elderly is unclear because those guidelines were developed based on studies of younger patients.

“As the population of very-elderly dialysis patients grows, nephrolo-gists must become more adept at addressing geriatric problems, such as dementia, falls, and depression, and the social and ethical challenges posed by the elderly,” the researchers wrote.

Given the increase in very-elderly patients with end-stage renal disease, the associated morbidity, mortality, and costs, Dr. Kurella's group concluded, research priorities should include determining the reasons for the increasing incidence and development of risk stratification indices to aid in dialysis decision-making.